(1) Field of the Invention
The present invention relates to an ink ribbon cartridge to be used in a printer. More particularly, the present invention relates to an ink ribbon protecting mechanism of an ink ribbon cartridge which prevents an ink ribbon contained in the ink ribbon cartridge from being brought down or twisted by vibration or shock caused during transportation or the like.
(2) Description of the Prior Art
In an ink ribbon cartridge to be used for a printer, an ink ribbon is folded at a predetermined pitch and contained in this folded state, and the contained ink ribbon is delivered out in succession by a feeding mechanism and used for the printing operation. An ink ribbon cartridge of this type ordinarily comprises a case member having in the interior thereof a container portion having a depth substantially equal to the width of the ink ribbon and also having an ink ribbon inlet and outlet and a lid member integrally associated with the case member. As such an ink ribbon cartridge, there can be mentioned one previously proposed by me in U.S. patent application Ser. No. 119,831 filed Feb. 8, 1980, now U.S. Pat. No. 4,325,646 issued Apr. 20, 1982. In this ink ribbon cartridge, both the case member and the lid member are constructed by thin molded articles of a synthetic resin, and both the side plates of the case member are supported by anchoring pawls formed on the lid member to prevent deformation thereof, and by securing the anchoring pawls to the case member, deformation of the lid member is prevented. By co-operation of such case member and lid member, a high rigidity is maintained in the ink ribbon cartridge though it is formed of a thin molded articles, and this ink ribbon cartridge is economically advantageous.
In the ink ribbon cartridge having the above-mentioned structure, the interior is quite hollow and empty, and there is disposed no member for supporting an ink ribbon folded at a predetermined pitch and contained in the interior of the ink ribbon cartridge. Accordingly, the ink ribbon is often brought down or twisted by vibration or shock during transportation or the like. There may be considered a method in which supporting members such as projections are formed in the interior of the ink ribbon cartridge and an ink ribbon is supported by such supporting members. However, if projections are formed in the interior of the ink ribbon cartridge, these projections hinder smooth travel of the ink ribbon when the printer is driven and the printing operation cannot be performed conveniently.